In actuators the driving (force-generating) device which has to transmit force and/or motion to a setting member to be served by the actuator, frequently cannot be directly coupled with the setting member; rather, such a coupling has to be effected by a transmission member, such as a push rod which, to ensure its exact longitudinal guidance, is guided in slide guides.
Particularly in actuators in which the transmission member has to be reciprocated with a high frequency and/or with a short stroke and/or with a low force input, the conventional slide guides for the transmission member have significant disadvantages. Apart from energy losses due to friction and wear, in short-stroke actuators in which a timing accuracy is essential, it is of disadvantage that the friction derived from slide guides results in interferences which can be neither qualified nor quantified.